Scorpius X-1

<a href="/facts/Celestial_coordinate_system/23HhqvHj">Coordinates</a>:  <a href="http://www.wikisky.org/?ra=16.331963888889&de=-15.640222222222&zoom=5&show_grid=1&show_constellation_lines=1&show_constellation_boundaries=1&show_const_names=1&show_galaxies=1&img_source=IMG_all">16h 19m 55.07s, −15° 38′ 24.8″</a>

<p>Scorpius X-1 is an <a href="/facts/X-ray/wseP79cN">X-ray</a> source located roughly 9000 <a href="/facts/Light_year/IGc5NdQb">light years</a> away in the constellation <a href="/facts/Scorpius_(constellation)/ddxFGlK0">Scorpius</a>. Scorpius X-1 was the first extrasolar X-ray source discovered, and, aside from the <a href="/facts/Sun/CadPCVHh">Sun</a>, it is the strongest apparent non-transient source of X-rays in the <a href="/facts/Sky/wwvQ84J1">sky</a>. The X-ray <a href="/facts/Flux/Aw3P5Bvb">flux</a> varies day-to-day, and is associated with an <a href="/facts/Visible_light/jeofpMn4">optically</a> visible <a href="/facts/Star/PFbd6ICx">star</a>, V818 Scorpii, that has an <a href="/facts/Apparent_magnitude/7pCTF1Me">apparent magnitude</a> which fluctuates between 12-13.
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Scorpius X-1 open-in-new

Scorpius X-1